1. Technical Field
The present disclosure relates to a phosphor wheel used in a light source device included in a projection image display apparatus, for example.
2. Description of the Related Art
Japanese Unexamined Patent Application Publication No. 2013-228598 discloses a phosphor wheel including a titanium oxide layer disposed on a substrate, and a phosphor layer disposed on the titanium oxide layer. Such a phosphor wheel includes a fluorescent light emitter disposed opposite to an excitation light source, and a fluorescence light-emitting plate including a reflection section which contains titanium oxide and is disposed on the opposite side of the excitation light source to be joined to the fluorescent light emitter. When excitation light from the excitation light source is emitted onto the fluorescent light emitter, the fluorescent light emitter converts a wavelength of the excitation light, and the fluorescent light whose wavelength has been converted is reflected off the reflection section.
The reflection section of such a phosphor wheel has a reflectance improved by the titanium oxide, and thus it is possible to increase light use efficiency and reduce its costs.